Hand planer

ABSTRACT

A manual planing machine, has a planer shaft having at least one longitudinal slot, an elongated flat planer knife clamped in a detachable manner in the and formed as a dual-cutting mini reversible tip with at least one cutter and with a back groove extending parallel to the cutter and with a holding rib on a side of the longitudinal slot to prevent an intentional detachment from the planer shaft, the planer knife carrying only one the cutter, extending in a corrugated manner in such a way that troughs of the cutter lie on a common first straight line having the same spacing relative to the back groove as a cutter of a mini reversible tip, while its crest lie on a common second straight line which extends 0.5-1.5 mm radially above the first straight line, the planar knife carrying a contact edge which is right-tangled and is flattened relative to a back, instead of another cutter at a side located opposite from the at least one cutter for support at the radial stop of the planar shaft.

BACKGROUND OF THE INVENTION

The invention is based on a manual planing machine, a planer shaft, aplaner knife and a spacer strip respectively.

DE-OS 91 52 65 discloses a planing machine with a cutter head or planershaft whose elongated planer knives extend over the width of the planershaft and can be clamped by clamping wedges which are carried by theplaner shaft and are actuated by centrifugal force. The known planingmachine is suitable only for clamping large-volume planer knives. Theconsiderably smaller and thinner carbide mini reversible tips, e.g., inthe standard size of 1.1 mm thickness and 5.5 mm height, cannot beclamped in any definite position in the known planing machines becausethey have a volume and mass roughly ten times smaller than thelarge-volume planer knives. The large-volume planer knife cannot beeconomically produced from carbide due to its large dimensions becausethe cost of carbide is very high, so that only high-speed steel planerknives of lesser stability and quality are considered for the knownplaners.

EP 01 17 991 discloses a planing machine with a planer shaft formed ofprofile disks, wherein a clamping wedge actuated by centrifugal force isarranged in the longitudinal groove of the planer shaft. This planershaft is also not suitable for receiving mini reversible tips, but onlyfor conventional high-power high-speed steel knives with an approximatethickness of 3 mm and a height of 11.5 mm. These would also be just asuneconomical as carbide knives in terms of construction.

Patent FR 2 477 460 discloses a clamping device at a planer shaft forlarge-volume rusticating planer knives with a corrugated cutter which,alternatively, can also receive dual-cutting straight mini reversibletips. For this purpose, a shavings or chip rejecting part is inserted ina longitudinal groove of the planer shaft, wherein this chip rejectingpart is supported at the groove flank located in front of the planerknife in the direction of rotation and clamps the planer knife againstthe other groove flank. The chip rejecter has, on its side facingradially outward, a corrugated profile corresponding to the large-volumerusticating cutter profile.

If a mini reversible tip is to be clamped instead of the rusticatingplaner knife, clamping cannot be carried out exclusively by the clampingwedge, but rather an additional clamping body is needed which clampsitself—and, in so doing, also the mini reversible tip—between theclamping wedge and the outer groove flank.

Clamping wedges of the type mentioned above are complicated to produceand are accordingly expensive. Further, the rusticating knife clampingwedge must be exchanged with standard clamping wedges with a straightchip rejecting part when using straight planer knives because of thecorrugated chip rejecting part. This complicates the exchanging ofplaner knives and, moreover, requires special storage for the differentclamping wedges.

The corrugated chip rejecting part is necessary for limiting chipthickness because the maximum chip thickness in rusticating planerknives is appreciably thicker than in straight planer knives. This isbecause the thinnest chips generated by the corrugation troughs of thecutter must also still have a sufficient thickness for high surfacequality. Therefore, the minimum chip thickness in rusticating knives isadapted to the minimum chip thickness of straight planer knives, whereinthe maximum chip thickness must be about one millimeter thicker than theminimum chip thickness for the rusticated texture to be visuallyeffective.

Since the risk of a back-kick increases with the chip thickness whenworking with the planer, the chip thickness is limited to a maximum 1.1mm.

SUMMARY OF THE INVENTION

The planing machine, planer shaft, planer knife and spacer stripaccording to the invention have the advantage over the prior art thatrusticating planer knives according to the invention can be clamped inthe same manner as mini reversible tips in their standard clampingdevices, so that there is no manufacturing cost for special outfittingfor rusticating knives.

By refashioning series-produced mini reversible tip blanks with athickness of 1.1 mm and a height of 5.5 mm as rusticating knives, theycan be clamped with conventional screw clamping means, but can also beclamped by means of centrifugal force. Due to the fact that theconstructional size is reduced by a factor of 10 compared withconventional high-speed steel rusticating knives, carbide rusticatingknives can, for the first time, be produced inexpensively with a servicelife approximately ten-times longer than that of previous rusticatingknives. Because of their small dimensions, the rusticating planer knivesaccording to the invention have the advantage over previous large-volumerusticating planer knives that they save considerable weight.

A chip rejecting part for limiting chip thickness can be inserted in anadditional, easily produced longitudinal groove of the planer shaft as aplastic strip without increasing weight. Therefore, the planer shafts,according to the invention, with centrifugal force clamping for minireversible tips are suitable for producing rustically textured workpiecesurfaces without resulting in substantially higher production costs thanfor previous planer shafts for straight dual-cutter mini reversible tipsor for other straight planer knives.

A rusticating knife which is particularly simple to produce from minireversible tips and, in addition, can be positioned radially in aparticularly exact manner relative to the planer shaft, and in whichchanges in position brought about by clamping are eliminated is providedin that the planer knife carries only one effective cutter withcorrugation troughs and corrugation crests, wherein the troughs lie on acommon first straight line having the same parallel spacing relative totheir back groove as straight standard cutters of conventional minireversible tips relative to their back groove, and the crests lie on acommon second straight line which extends 0.5 mm to 1.5 mm above thefirst straight line, and in that the planer knife carries a flattenedcontact edge instead of a second cutter at its side located oppositefrom the first cutter for support at the radial stop of the planershaft, wherein the parallel spacing of the contact edge relative to theback groove is 0.5 to 1.5 mm smaller than the parallel spacing betweenthe back groove and the opposite corrugation troughs. Therefore, themanual planers according to the invention can be produced more simply,more economically and so as to be more efficient. This advantage is alsoprovided in that the planer knife with the corrugated cutter is 1.1 mmthick, 5.5 mm high and as wide as the planer shaft and is preferablymade of carbide.

The planing machine and planer shaft are lighter and can be produced ina simpler manner in that another longitudinal slot is arranged parallelin front of the first longitudinal slot for receiving a spacer strip forlimiting chip thickness.

The spacer strip can be arranged at the planer shaft so as to preventits loss in that the longitudinal slot for receiving the spacer striphas a cross-shaped cross section with at least one shoulder recess.Compared with previous planer shafts, the spacer strip which is made ofplastic results in reduced weight because the additional longitudinalslot reduces the mass of the planer shaft more than the spacer stripincreases the total mass of the planer shaft.

Due to the fact that the outer edge of the spacer strip projecting overthe outer contour of the planer shaft is corrugated and extends along aflight diameter which is 1 mm smaller than the cutter of the planerknife, its function as a chip thickness limiter is ensured. A slotclosure which extends flush with the outer contour of the planer shaftand which is alternatively adjustable for limiting chip thickness isprovided in that the edge of the spacer strip located opposite from theouter edge with the corrugated contour has a straight contour. Further,the spacer strip is also secured by the lateral shoulder against axialdisplacement and protected from falling out of the longitudinal slot.

BRIEF DESCRIPTION OF THE DRAWING

An embodiment example of the invention is explained more fully in thefollowing with reference to the description and accompanying drawing.

FIG. 1 shows a side view of the planer according to the invention;

FIG. 2 shows a top view of the back of a rusticating planer knifeaccording to the invention;

FIG. 3 shows a three-dimensional view of a planer shaft, according tothe invention, with rusticating planer knives;

FIG. 4 shows a side view of the planer shaft according to FIG. 3; and

FIG. 5 shows a spacer strip for limiting chip thickness for use in theplaner shaft according to the invention.

DESCRIPTION OF THE PREFERRED EXAMPLE

The manual planing machine 10 shown in a side view in FIG. 1 is formedof a machine housing 12 with a motor housing 14 and a handle 16. Thehandle 16 carries an electric switch 18.

A planer shaft 20 is mounted in the machine housing 12 so as to berotatable about its axis 19 in the direction of the arrow 11 indicatingthe rotating direction. This planer shaft 20 carries two planer knives21, each having a corrugated (FIG. 2) cutter 2, in front of which chipgrooves 25 are shaped into the outer contour 23 of the planer shaft 20.

During rotation of the planer shaft 20, the knives 21, with theircutters 22, determine a flight circle 24, shown in dash-dot lines, whichprojects over the base 26 of the manual planing machine 10, so that thecutters 22 can engage in a cutting manner in a workpiece 27 extendingflush with the base 26. An opening 28 arranged in the base 26 for thepassage of the cutters 22 at the bottom can be closed by means of apendulum-type protective hood 30. The latter closes the opening 28automatically as soon as the manual planing machine 10 is lifted fromthe workpiece 27. This reduces the risk of injury to the user on therotating cutters 22.

The machine housing 12 has lateral recesses 32 at both sides of theplaner shaft 20 in the area of the base 26 through which, from the side,the planer knives 21 can be removed from the planer shaft 20 or insertedtherein for clamping. By means of centrifugal wedges 56, which will bedescribed in the following with reference to FIG. 3, the planer knives21 are automatically clamped in a reliable manner when the manual planer10 is put into operation.

A view of the planer knife 21 from the back shown as a detail in FIG. 2shows its corrugated contoured cutter 22 with crests 38 and troughs 39.The crests 38 lie on a common straight line 0 and the troughs 39 lie ona common straight line U. A back groove 35 which serves to engage over alongitudinal rib 37 (FIG. 4) of the planer shaft 20 runs in the centerof the back 34 along its entire length. A center line C of the backgroove 35 is the reference line for the degree of spacing a, b withrespect to the common straight line U of the troughs 39 and with respectto the contact edge 36 on the side located opposite from the cutter 22.

The planer shaft 20 shown in the three-dimensional view in FIG. 3 has asubstantially circular outer contour 23. To reduce weight, the planershaft 20 forms a hollow section with two symmetrical, oppositelylocated, axially parallel recesses 42, 43, 44, 45. Because of theirspecial contour which opens radially outward into a longitudinal slot 46at one location in each instance, each of the recesses 44, 45 forms aportion of the planer shaft 20 which passes into a centrifugal wedge 56via a leaf spring 54. The planer knives 21 which are formed as thin minireversible tips are mounted on two sides located radially opposite oneanother in the longitudinal slots 46, wherein the cutters 22, the backgroove 35 and the contact edge 36 can be seen clearly.

The planer knives 21 are clamped in the longitudinal slot 46 of theplaner shaft 20 between groove flanks, not shown in more detail. Thelongitudinal slot 46 proceeds radially inward from the outer contour 23,via a longitudinal rib 37 (FIG. 4) engaging in the back groove 35 of theplaner knife 21, into a right-angled transverse step 50 projecting in astraight line. Following the latter, the longitudinal slot 46 widens outtoward the recess 44. This is designed in such a way that an area of theplaner shaft 20 which is thinner toward the outer contour 23 forms aleaf spring 54 which becomes thicker toward a centrifugal wedge 56.

The centrifugal wedge 56 engages around the projection 50 with a catchgroove 58 and, with its straight side which leads radially outward,forms the left flank of the longitudinal slot 46 which passes radiallyoutward into the chip groove 25. This flank is arranged at an angle suchthat there is no self-locking between the centrifugal wedge 56 and theplaner knife 21 when the centrifugal wedge 56 contacts the flat side ofthe planer knife 21. The centrifugal wedge 56 accordingly always returnsagain to its release position because there is no longer any centrifugalforce as soon as the planer shaft 20 is at a standstill. Thisfacilitates exchange of planer knives.

The catch groove 58 enclosing the transverse step 50 defines the radialstroke of the centrifugal wedge 56 inward and outward to preventoverstretching of the leaf spring 54. The pretensioning of the leafspring 54 is selected in such a way that the planer knife 21 cannotchange its axial position with respect to the longitudinal slot 46 in anunwanted manner or fall out when the planer shaft 20 is stopped. Byinserting a screwdriver blade or hexagon shaft into the area of therecess 44 on the right-hand side considered in the viewing direction,the centrifugal wedge 56 can be swiveled radially inward and thecentrifugal wedge 56 accordingly occupies its release position in whichthe planer knives 21 slide out of the longitudinal slot 46 automaticallyin the vertical position of the planer shaft 20 or planer 10.

FIG. 4 shows a side view of the planer shaft 20, wherein the axle 9 ofthe planer shaft 20 carries the planer shaft body.

The planer shaft 20 carries the planer knife 21 with the corrugatedcutter 22 at top in the viewing direction. This planer knife 21, alsocalled a rusticating planer knife, has the same outer dimensions as minireversible tips with straight cutters and can easily be exchanged forstraight cutters of this type.

It can be seen clearly in FIGS. 3, 4 how the planer knife 21 issupported by its flattened contact edge 36 on the radial inside at thetransverse step 50 projecting vertical to the planer knife 21. Thismakes possible a particularly safe radial positioning of the cutter 22and accordingly also an accurate adjustment of the flight circle 24. Thelongitudinal rib 37 serves only to engage in the back of the planerknife 21 as is conventional with mini reversible tips in order toprevent it from exiting the longitudinal slot 46 unintentionally.

If a dual-cutter mini reversible tip is clamped in the planer shaft 20instead of the rusticating planer knife 21, its cutter on the radialinner side contacts the transverse step 50, which ensures that theradial outer cutter is positioned especially accurately.

Formerly, a contact edge directed diagonally corresponding to thecutting angle of the mini reversible tip was used instead of atransverse step, wherein even small manufacturing defects weresufficient to lead to considerable radial positional deviations of theradial outer cutter. The transverse step 50 makes possible aparticularly reliable and exact positioning of the planer knife 21.

Another longitudinal slot 48 with a cross-shaped cross section which isopen on the radial outer side is arranged following the arrow 52indicating the rotating direction at the left of the planer knife 21considered in the viewing direction, wherein a spacer strip 60 can beinserted into the cross section so as to prevent it from falling out.The spacer strip 60 is corrugated on its radial outer edge 62 and has astraight contour on its radial inner edge 64. On the right-hand andleft-hand side, the spacer strip 60 carries a shoulder 61 for positiveengagement in the cross-shaped longitudinal slot 48. The spacer strip 60can be reversed in that its corrugated side which was previously locatedon the outer side is now located on the radial inside, and wherein thestraight edge 64 terminates flush with the outer contour 23 of theplaner shaft 20.

FIG. 5 shows the spacer strip 60 as a detail viewed on the longitudinalside. The corrugated edge 62 located on the radial outer side duringoperation with the rusticating planer knife 21 can be seen clearly, ascan the shoulders 61. The left side of the spacer strip 60 considered inthe viewing direction is formed as an end piece 66 which is widened in aT-shaped manner and which, when inserted farther into the longitudinalslot 48, prevents further axial displacement of the spacer strip 60 andaccordingly fixes its axial position relative to the planer shaft 20.

What is claimed is:
 1. A manual planing machine, comprising a planerhousing; a planer shaft carried by said planer housing and having atleast one longitudinal slot of such a configuration that saidlongitudinal slot can fittingly receive only planer knives of minireversible tip type; an elongated flat planer knife clamped in adetachable manner in said at least one longitudinal slot, said planerknife having only one cutting edge located on one side thereof and aback groove extending parallel to said cutting edge, said planer shafthaving a holding rib on a side of said longitudinal slot said backgroove engaging said holding rib to prevent an unintentional detachmentfrom said planer shaft; at least one stop provided at a side of saidlongitudinal slot and formed so that said planer knife is supported onsaid at least one stop radially for fixing said cutting edge on aprovided flight circle, said cutting edge extending in a corrugatedmanner in such a way that troughs of said cutting edge lie on a commonfirst straight line having a same spacing relative to said back grooveas a cutting edge of the planer knife of a mini reversible tip typewhile crests of said cutting edge lie on a common second straight linewhich extends 0.5-1.5 mm radially above said first straight line, saidplaner knife having a contact edge which is flattened and right-angledrelative to a back side of the planer knife cutting edge, said contactedge being provided on a side of the planer knife located opposite tosaid one side of the planer knife for support at said radial stop ofsaid planer shaft.
 2. A manual planing machine as defined in claim 1,wherein said contact edge has a parallel spacing relative to said backgroove which is 0.5-1.5 mm smaller than a parallel spacing between saidback groove and said opposite corrugation troughs.
 3. A manual planingmachine as defined in claim 1, wherein said stop is arranged at a sideof said longitudinal slot so as to project forward at a right angle,said contact edge of said planar knife extending substantially parallelto said stop.
 4. A manual planing machine as defined in claim 1, whereinsaid planar knife is 1.1 mm thick, 5.5 mm high, and essentially as longas said planar shaft is wide, said planar knife being composed of amaterial selected from a group consisting of carbide and high-powerhigh-speed steel.
 5. A manual planing machine comprising a planerhousing: a planer shaft carried by said planer housing and having atleast one longitudinal slot of such a configuration that saidlongitudinal slot can fittingly receive only planer knives of a minireversible tip type, an elongated flat planer knife clamped in adetachable manner in said at least one longitudinal slot, said planerknife having only one cutting edge provided on one side thereof and aback groove extending parallel to said cutting edge, said planer shafthaving a holding rib on a side of said longitudinal slot, said backgroove engaging said holding rib to prevent an unintentional detachmentfrom said planer shaft; at least one stop provided at a side of saidlongitudinal slot and formed so that said planer knife is supported onsaid at least one stop radially for fixing said cutting edge on aprovided flight circle, said cutting edge extending in a corrugatedmanner in such a way that troughs of said cutting edge lie on a commonfirst straight line having a same spacing relative to said back grooveas a cutting edge of the planer knife of a mini reversible tip typewhile crests of said cutting edge lie on a common second straight linewhich extends 0.5-1.5 mm radially above said first straight line, saidplaner knife having a contact edge which is flattened and right-angledrelative to a back side of the planer knife, said contact edge beingprovided on a side at the planer knife located opposite to said one sideof the planer knife for support at said radial stop of said planershaft; and an additional longitudinal slot arranged substantiallyparallel to said longitudinal slot and having a cross-section with atleast one shoulder recess; and further comprising a spacer stripreceived in said additional longitudinal slot.
 6. A manual planingmachine as defined in claim 5, wherein said spacer strip is composed ofplastic and has a cross-shaped cross-section so that it is insertableinto said additional longitudinal slot and is prevented from fallingout.
 7. A manual planing machine as defined in claim 5, wherein saidspacer ring has one outer edge having a corrugated contour and projectsover an outer contour of said planar shaft when inserted into saidadditional longitudinal slot, said one outer edge of said spacerextending along a flight diameter which is 1 mm smaller than said cutterof said planar knife.
 8. A manual planing machine as defined in claim 7,wherein said spacer ring has an outer edge which is located opposite tosaid outer edge with said corrugating contour and has a straightcontour, said outer edge with said straight contour extending flush withsaid outer contour of said planar shaft when inserted into saidadditional longitudinal slot so as to face radially outwards.
 9. Amanual planing machine as defined in claim 5, wherein said spacer ribhas at least one lateral shoulder for securing against axialdisplacement and for preventing falling out of said longitudinal slot.10. A manual planing machine as defined in claim 1; and furthercomprising an additional longitudinal slot arranged parallel to saidlongitudinal slot viewed in a rotating direction of said planar shaftand having a cross-shaped cross-section with at least one shoulderrecess; and a spacer strip received in said additional longitudinalslot.
 11. A planer knife for a manual planing machine, having only onecutting edge provided one the side thereof, said planer knife includinga back groove extending parallel to said cutting edge, and a contactedge provided on a side of the planer knife opposite to said one side,said cutting edge extending in a corrugated manner in such a way thattroughs thereof lie on a common first straight line having a samespacing relative to said back groove, said cutting edge also havingcrests which are located on a common second straight line extending0.5-1.5 mm radially above said first straight line; said contact edgebeing formed as a right-angle contact edge which is flattened relativeto a back side of the planer knife for supporting at a radial stop of aplaner shaft.
 12. A planar knife as defined in claim 11, wherein saidcontact edge has a parallel spacing relative to said back groove of0.5-1.5 mm smaller than a parallel spacing between said back groove andsaid corrugation troughs.
 13. A planar knife as defined in claim 12,wherein said planar knife is 1.1 mm thick, 5.5 mm high, and as wide assaid planar shaft, said planar knife being composed of a materialselected from the group consisting of carbide and high-power high-speedsteel.
 14. A spacer strip for insertion into a planer shaft of a manualplaning machine, said spacer strip having a strip element composed ofplastic and having a cross-shaped cross-section such that it isinsertable into a longitudinal slot of the planer shaft so as to beprevented from falling out, wherein said strip element has a corrugatedcontour and projects over an outer contour of the planer shaft wheninserted into the longitudinal slot, said strip element extending alonga flight diameter which is approximately 1 mm smaller than a cuttingedge of the planer knife.
 15. A planar knife as defined in claim 14,wherein said strip element has an edge which is located opposite to anouter edge with a corrugated contour and has a straight contour, saidedge extending flush with an outer contour of the planar shaft wheninserted into an additional longitudinal slot.
 16. A planar knife asdefined in claim 14, wherein said strip element has at least one lateralshoulder preventing it from falling out of the longitudinal slot.